Verify User Who Owns Backup group File

Docs > Datadog Security > OOTB Rules > Verify User Who Owns Backup group File

Description

To properly set the owner of /etc/group-, run the command:

$ sudo chown root /etc/group-

Rationale

The /etc/group- file is a backup file of /etc/group, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.

Remediation

Shell script

The following script can be run on the host to remediate the issue.

#!/bin/bash

if id "0" >/dev/null 2>&1; then
  newown="0"
fi
if [[ -z ${newown} ]]; then
  echo "0 is not a defined user on the system"
  exit 1
fi
chown $newown /etc/group-

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: Set the file_owner_backup_etc_group_newown variable if represented by uid
  set_fact:
    file_owner_backup_etc_group_newown: '0'
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Test for existence /etc/group-
  stat:
    path: /etc/group-
  register: file_exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed

- name: Ensure owner on /etc/group-
  file:
    path: /etc/group-
    owner: '{{ file_owner_backup_etc_group_newown }}'
  when: file_exists.stat is defined and file_exists.stat.exists
  tags:
  - NIST-800-53-AC-6 (1)
  - PCI-DSS-Req-8.7.c
  - PCI-DSSv4-2.2
  - PCI-DSSv4-2.2.6
  - configure_strategy
  - file_owner_backup_etc_group
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed